Also: http://wattsupwiththat.com/2012/11/...rds/#more-73752 "The ‘Younger Dryas’ episode lasted for approximately 1,300 years (starting at *12,800 BP), covered spatially both Hemispheres and ended even more suddenly than it emerged when temperatures increased regionally up to 15 oC in few decades (Alley et al. 1993). Although the cause for this short return to an ice age period is still under debate, it has become clear that it is not associated with a single catastrophic event (such as the release of freshwater from the lake Agassiz in Gulf of Mexico or the impact of a comet) but is rather regarded as an integral part of natural variability (Broecker et al. 2010; Mangerud et al. 2010)." ...and this thread should probably be split at Kristus' post.